Damage avoidance system for unmanned aerial vehicle

ABSTRACT

This disclosure describes an unmanned aerial vehicle (“UAV”) and system that may perform one or more techniques for protecting objects from damage resulting from an unintended or uncontrolled impact by a UAV. As described herein, various implementations utilize a damage avoidance system that detects a risk of damage to an object caused by an impact from a UAV that has lost control and takes steps to reduce or eliminate that risk. For example, the damage avoidance system may detect that the UAV has lost power and/or is falling at a rapid rate of descent such that, upon impact, there is a risk of damage to an object with which the UAV may collide. Upon detecting the risk of damage and prior to impact, the damage avoidance system activates a damage avoidance system having one or more protection elements that work in concert to reduce or prevent damage to the object upon impact by the UAV.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application62/039,377, filed Aug. 19, 2014, entitled “Protecting Automated AerialVehicles From Impact Damage,” which is incorporated herein by referencein its entirety.

BACKGROUND

Unmanned aerial vehicles are continuing to increase in use. For example,unmanned aerial vehicles are often used for surveillance. While thereare many beneficial uses of unmanned aerial vehicles, they also havemany drawbacks. For example, unmanned aerial vehicles that utilize fourpropellers for flight (a/k/a, quad-copters) become unstable if two ormore of the propellers lose power or become damaged. Similarly, if thenavigation system becomes inoperable, the power supply is depleted,etc., and continued flight of the unmanned aerial vehicle may not bepossible.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical components or features.

FIG. 1A depicts a block diagram of a top-down view of an unmanned aerialvehicle with a damage avoidance system, according to an implementation.

FIG. 1B depicts a block diagram of a damage avoidance system of anunmanned aerial vehicle, according to an implementation.

FIGS. 1C and 1D are circuit diagrams illustrating example deploymentcircuits for deploying the protection element 120, according to animplementation.

FIGS. 2A-2C depict block diagrams of a side view of an unmanned aerialvehicle, according to an implementation.

FIGS. 3A-3B depict block diagrams of another side view of an unmannedaerial vehicle, according to an implementation.

FIGS. 4A-4B depict block diagrams of a top-down view of an unmannedaerial vehicle with a damage avoidance system, according to animplementation.

FIG. 5 depicts another block diagram of a side view of an unmannedaerial vehicle, according to an implementation.

FIG. 6 depicts another block diagram of a side view of an unmannedaerial vehicle, according to an implementation.

FIG. 7 depicts another block diagram of a side view of an unmannedaerial vehicle, according to an implementation.

FIG. 8A illustrates an unmanned aerial vehicle having a reorientationelement that includes a rotational modifier, according to animplementation.

FIG. 8B illustrates a reorientation element that includes the rotationalmodifier of FIG. 8A in one possible position, according to animplementation.

FIG. 8C illustrates a reorientation element that includes the rotationalmodifier of FIG. 8A in another possible position, according to animplementation.

FIG. 9A illustrates a reorientation element that may be included in anunmanned aerial vehicle, according to an implementation.

FIG. 9B illustrates another reorientation element that may be includedin an unmanned aerial vehicle, according to an implementation.

FIG. 10 is a diagram of an unmanned aerial vehicle environment,according to an implementation.

FIG. 11 is a flowchart illustrating a process for protecting an objectfrom impact by an unmanned aerial vehicle, according to animplementation.

FIG. 12 is a flowchart illustrating another process for protecting anobject from impact by an unmanned aerial vehicle, according to animplementation.

FIG. 13 is a block diagram illustrating various components of anunmanned aerial vehicle control system, according to an implementation.

FIG. 14 is a block diagram of an illustrative implementation of a serversystem that may be used with various implementations.

While implementations are described herein by way of example, thoseskilled in the art will recognize that the implementations are notlimited to the examples or drawings described. It should be understoodthat the drawings and detailed description thereto are not intended tolimit implementations to the particular form disclosed but, on thecontrary, the intention is to cover all modifications, equivalents andalternatives falling within the spirit and scope as defined by theappended claims. The headings used herein are for organizationalpurposes only and are not meant to be used to limit the scope of thedescription or the claims. As used throughout this application, the word“may” is used in a permissive sense (i.e., meaning having the potentialto), rather than the mandatory sense (i.e., meaning must). Similarly,the words “include,” “including,” and “includes” mean including, but notlimited to.

DETAILED DESCRIPTION

This disclosure describes an unmanned aerial vehicle (“UAV”) and systemthat may perform one or more techniques for protecting an object and/orthe UAV from damage resulting from an impact between the object (e.g.,animal, automobile, building, ground) and the UAV. As described herein,various implementations utilize a damage avoidance system that detects arisk of damage to an object caused by an uncontrolled impact by the UAVand takes steps to reduce or eliminate that risk of damage to theobject. For example, the damage avoidance system may detect that the UAVhas lost power, is not following a designated flight path, and/or isdescending at a rapid rate of descent such that, upon impact, there is arisk of damage to an object with which the UAV may collide. Upondetecting the risk of damage and prior to impact, the damage avoidancesystem activates a protection system having one or more protectionelements that work in concert to reduce or prevent damage to the objectupon impact. Reducing and/or preventing damage to the object may, insome instances, also reduce or prevent damage to the UAV. Howeverprotecting the UAV may be of secondary consideration.

To illustrate a specific example, an UAV may be equipped with a damageavoidance system that includes a safety monitoring system and aprotection system. If the UAV, for example, is descending at anuncontrolled rate, the safety monitoring system, through use of variousdetection elements described below, measures a distance from anapproaching object and determines a velocity of the UAV toward thatobject. Based on the collected information, the safety monitoring systemdetermines whether the risk of damage to the object, that will be causedby the impending impact, exceeds an acceptable threshold. If the safetymonitoring system determines that the risk of damage exceeds theacceptable threshold, the protection system is activated. The protectionsystem, in this example, causes the UAV to be reoriented, if necessary,and deploys a parachute prior to impact such that the parachute slowsthe rate of descent of the UAV, thereby reducing the forces at impactwith the object.

In some implementations, the parachute may be deployed ballistically tospeed the deployment of the parachute. For example, a mass may betethered to the canopy of the parachute. When the mass is deployed fromthe UAV, it pulls the parachute from the protection element housing sothat the canopy can be fully deployed in seconds. In otherimplementations, deployment of the parachute may be accelerated throughuse of a compressed gas cartridge (e.g., carbon dioxide, air),solid-fuel rocket, a cartridge containing an incompressible liquid,jets, and the like. For example, a cartridge filled with water (anincompressible liquid) may be attached to the parachute. To deploy thecartridge, a gas (e.g., air) is introduced into the cartridge causingthe water to expel from the cartridge and deploy the cartridge from theUAV.

This brief introduction is provided for the reader's convenience and isnot intended to limit the scope of the technology described herein.Several example implementations and contexts are provided hereinafterwith reference to the following figures, as described below in moredetail. However, the following implementations and contexts are but afew of many.

While the examples discussed herein primarily focus on UAVs in the formof an aerial vehicle utilizing multiple propellers to achieve flight(e.g., a quad-copter or octo-copter), it will be appreciated that theimplementations discussed herein may be used with other forms of UAVs.

A “relay location,” as used herein, may include, but is not limited to,a delivery location, a materials handling facility, a cellular tower, arooftop of a building, a delivery location, or any other location wherean UAV can land, charge, retrieve inventory, replace batteries, and/orreceive service.

As used herein, a “materials handling facility” may include, but is notlimited to, warehouses, distribution centers, cross-docking facilities,order fulfillment facilities, packaging facilities, shipping facilities,rental facilities, libraries, retail stores, wholesale stores, museums,or other facilities or combinations of facilities for performing one ormore functions of materials (inventory) handling.

A “delivery location,” as used herein, refers to any location at whichone or more inventory items may be delivered. For example, the deliverylocation may be a person's residence, a place of business, a locationwithin a materials handling facility (e.g., packing station, inventorystorage), any location where a user or inventory is located, etc.Inventory or items may be any physical goods that can be transportedusing an UAV.

FIG. 1A illustrates a block diagram of a top-down view of an UAV 100with a damage avoidance system 101, according to an implementation. Thedamage avoidance system 101 is discussed in further detail below withrespect to FIG. 1B.

As illustrated, the UAV 100 includes eight propellers 102-1, 102-2,102-3, 102-4, 102-5, 102-6, 102-7, 102-8 spaced about the frame 104 ofthe UAV. The propellers 102 may be any form of propeller (e.g.,graphite, carbon fiber) and of a size sufficient to lift the UAV 100 andany inventory engaged by the UAV 100 so that the UAV 100 can navigatethrough the air, for example, to deliver an inventory item to alocation. While this example includes eight propellers, in otherimplementations, more or fewer propellers may be utilized. Likewise, insome implementations, the propellers may be positioned at differentlocations on the UAV 100. In addition, alternative methods of propulsionmay be utilized. For example, fans, jets, turbojets, turbo fans, jetengines, and the like may be used to propel the UAV.

The frame 104 or body of the UAV 100 may likewise be of any suitablematerial, such as graphite, carbon fiber and/or aluminum. In thisexample, the frame 104 of the UAV 100 includes four rigid members 105-1,105-2, 105-3, 105-4, or beams arranged in a hash pattern with the rigidmembers intersecting and joined at approximately perpendicular angles.In this example, rigid members 105-1 and 105-3 are arranged parallel toone another and are approximately the same length. Rigid members 105-2and 105-4 are arranged parallel to one another, yet perpendicular torigid members 105-1 and 105-3. Rigid members 105-2 and 105-4 areapproximately the same length. In some implementations, all of the rigidmembers 105 may be of approximately the same length, while in otherimplementations, some or all of the rigid members may be of differentlengths. Likewise, the spacing between the two sets of rigid members maybe approximately the same or different and/or the orientation of therigid members with respect to other rigid members and/or the frame 104of the UAV may also vary.

While the implementation illustrated in FIG. 1A includes four rigidmembers 105 that are joined to form the frame 104, in otherimplementations, there may be fewer or more components to the frame 104.For example, rather than four rigid members, in other implementations,the frame 104 of the UAV 100 may be configured to include six rigidmembers. In such an example, two of the rigid members 105-2, 105-4 maybe positioned parallel to one another. Rigid members 105-1, 105-3 andtwo additional rigid members on either side of rigid members 105-1,105-3 may all be positioned parallel to one another and perpendicular torigid members 105-2, 105-4. With additional rigid members, additionalcavities with rigid members on all four sides may be formed by the frame104. As discussed further below, a cavity within the frame 104 may beconfigured to include an inventory engagement mechanism for theengagement, transport and delivery of item(s) and/or containers thatcontain item(s).

In some implementations, the UAV may be configured for aerodynamics. Forexample, an aerodynamic housing may be included on the UAV that enclosesthe UAV control system 110, one or more of the rigid members 105, theframe 104 and/or other components of the UAV 100. The housing may bemade of any suitable material(s), such as graphite, carbon fiber,aluminum, etc. Likewise, in some implementations, the location and/orthe shape of the inventory (e.g., item or container) may beaerodynamically designed. For example, in some implementations, theinventory engagement mechanism may be configured such that, when theinventory is engaged, it is enclosed within the frame and/or housing ofthe UAV 100 so that no additional drag is created during transport ofthe inventory by the UAV 100. In other implementations, the inventorymay be shaped to reduce drag and provide a more aerodynamic design ofthe UAV and the inventory. For example, if the inventory is a containerand a portion of the container extends below the UAV when engaged, theexposed portion of the container may have a curved shape.

The propellers 102 and corresponding propeller motors are positioned atboth ends of each rigid member 105. For inventory transport purposes,the propeller motors may be any form of motor capable of generatingenough speed with the propellers to lift the UAV 100 and any engagedinventory thereby enabling aerial transport of the inventory. Forexample, for these purposes, the propeller motors may each be aFX-4006-13 740 kv multi rotor motor. As will be described in more detailbelow, when the propeller motors are to be utilized for electricitygeneration procedures, they may also be any form of motor (e.g.,permanent magnet, brushless, etc.) capable of generating electricitywhen the propellers are turned by an airflow (e.g., from a wind or therelative movement of the UAV 100 through the air).

Extending outward from each rigid member is a support arm 106 that isconnected to a safety barrier 108. In this example, the safety barrieris positioned around and attached to the UAV 100 in such a manner thatthe motors and propellers 102 are within the perimeter of the safetybarrier 108. The safety barrier may be plastic, rubber, etc. Likewise,depending on the length of the support arms 106 and/or the length,number or positioning of the rigid members 105, the safety barrier maybe round, oval, or any other shape.

Mounted to the frame 104 is the UAV control system 110. In this example,the UAV control system 110 is mounted in the middle and on top of theframe 104. The UAV control system 110, as discussed in further detailbelow with respect to FIG. 13, controls the operation, routing,navigation, communication, electricity generation procedures, and theinventory engagement mechanism of the UAV 100.

Likewise, the UAV 100 includes one or more power modules 112. In thisexample, the UAV 100 includes two power modules 112 that are removablymounted to the frame 104. The power module for the UAV may be in theform of battery power, solar power, gas power, super capacitor, fuelcell, alternative power generation source, or a combination thereof. Forexample, the power modules 112 may each be a 6000 mAh lithium-ionpolymer battery, polymer lithium ion (Li-poly, Li-Pol, LiPo, LIP, PLI orLip) battery. The power module(s) 112 are coupled to and provide powerfor the UAV control system 110 and the propeller motors.

In some implementations, one or more of the power modules may beconfigured such that it can be autonomously recharged, removed and/orreplaced with another power module while the UAV is landed. For example,when the UAV lands at a delivery location, relay location and/ormaterials handling facility, the UAV may engage with a charging memberat the location that will recharge the power module and/or the powermodule may be removed and replaced.

As mentioned above, the UAV 100 may also include an inventory engagementmechanism 114. The inventory engagement mechanism may be configured toengage and disengage items and/or containers that hold items. In thisexample, the inventory engagement mechanism 114 is positioned within acavity of the frame 104 that is formed by the intersections of the rigidmembers 105. The inventory engagement mechanism may be positionedbeneath the UAV control system 110. In implementations with additionalrigid members, the UAV may include additional inventory engagementmechanisms and/or the inventory engagement mechanism 114 may bepositioned in a different cavity within the frame 104. The inventoryengagement mechanism may be of any size sufficient to securely engageand disengage containers that contain inventory. In otherimplementations, the engagement mechanism may operate as the container,containing the inventory item(s) to be delivered. The inventoryengagement mechanism communicates with (via wired or wirelesscommunication) and is controlled by the UAV control system 110.

While the implementations of the UAV discussed herein utilize propellersto achieve and maintain flight, in other implementations, the UAV may beconfigured in other manners. For example, the UAV may include fixedwings and/or a combination of both propellers and fixed wings. Forexample, the UAV may utilize one or more propellers to enable takeoffand landing and a fixed wing configuration or a combination wing andpropeller configuration to sustain flight while the UAV is airborne.

FIG. 1B provides additional details of the damage avoidance system 101,included in the UAV 100, according to an implementation. The damageavoidance system 101 is capable of detecting whether there is a risk ofdamage to an object that exceeds a damage risk threshold and takingsteps to reduce or eliminate that risk.

The damage avoidance system 101 includes a safety monitoring system 103and a protection system 107. The safety monitoring system 103 includesone or more monitoring elements that determine/measure various statesand/or information related to the UAV 100. For example, the safetymonitoring system 103 may include monitoring elements such as a distancedetector 109, a motion detector 111, a system operability detector 113,an object type detector 115, and an energy detector 117. As will beappreciated, more or fewer monitoring elements may be included in thesafety monitoring system 103.

The distance detector 109 may be any number of components that canmeasure/determine the distance between the UAV 100 or damage avoidancesystem 101 and an object (not shown), such as an animal, an automobile,a building, the ground, etc. For example, the distance detector 109 canuse a sound or light generator/source (e.g., radar, sonar, laser,infra-red) in conjunction with a receptor/receiver to capture thereflection of the generated sound or light wave to determine/calculatethe distance between UAV 100 and the object. In some implementations,the distance detector 109 periodically measures/determines a distancebetween the UAV 100 and objects. In other implementations, the distancedetector 109 continuously measures a distance between the UAV 100 andnearby objects to maintain a relative altitude of the UAV above thoseobjects. The distance detector 109 may be disabled until a triggeringevent occurs or, alternatively, may always be enabled. A triggeringevent may be any scenario in which the UAV may unintentionally collidewith an object. For example, a triggering event may be determined if oneor more of the detectors of the safety monitoring system 103 collectsdata and determines that the UAV 100 is descending at an uncontrolledrate. Likewise, a triggering event may be determined if the systemoperability detector 113 collects data and determines that the UAVcontrol system is not functioning properly (e.g., the UAV is notfollowing an intended flight path or not responding to controlinstructions) and/or has lost power.

The motion detector 111 measures/determines movement of the UAV 100. Forexample, the motion detector 111 may measure acceleration or motion ofthe UAV 100. The motion detector 111 may include, for example, anaccelerometer or any type of motion detection device. In someimplementations, the motion detector 111 may receive input data fromcomponents, such as an accelerometer and/or the distance detector 109,and calculate a velocity of the UAV 100 and/or a rate of descent of theUAV 100 based at least in part on the received input data.Alternatively, the motion detector 111 can use existing circuit(s) ofthe UAV 100, components of the UAV control system 110 (FIG. 13), and/ordedicated elements in communication with the motion detector 111 tocollect data and determine the velocity of the UAV 100. For example, thenavigation system 1308 of the UAV control system 110 may providealtitude information, velocity, etc., that are used by the motiondetector 111 to determine a rate of descent of the UAV 100. The motiondetector 111 may also include a sound or light generator/source inconjunction with a detector/receiver to capture the reflection of agenerated sound or light wave to calculate the velocity of UAV 100.

The system operability detector 113 is configured to monitor theoperability of the UAV 100 and/or components of the UAV, such as the UAVcontrol system 110. For example, the system operability detector 113 maymonitor the position of the UAV 100 to ensure that is following theflight path 1326 specified by the UAV control system 110. Likewise, thesystem operability detector 113 may also monitor for powerinterruptions, loss of communication, rotational speed of the propellersand/or propeller motors, etc.

The object type detector 115 may determine the type of object that theUAV 100 is approaching when moving toward an object. For example, theobject type detector 115 may measure whether the object is a solid, hardobject (e.g., concrete, soil, building), a softer object (e.g., tree,water, snow), an animate object (e.g., animal), an inanimate object(e.g., building, automobile), or the like. It may be determined that anobject is animate by using a thermal sensor to detect heat generated bythe object.

The object type detector 115 may also determine the relative valueand/or ability of the object to absorb or reflect the energy from theimpact of the UAV 100 and the object. The relative value may be measuredor identified as a hardness or firmness of the object. The object typedetector 115 may use a number of technologies, such as infra-red, radar,x-ray or image recognition, to perform the determination of the objecttype. For example, using image recognition, the UAV 100 may include acamera and image recognition software. The camera can capture images ofthe object and, using image recognition techniques, the type of objectmay be determined. As discussed below, the damage avoidance system 101may use the object type in determining whether the risk of damage to theobject exceeds a damage risk threshold (in consideration with data fromthe other components of the safety monitoring system 103) and/or toselect one or more protection elements to deploy.

The energy detector 117 may determine the amount of kinetic energy at animpact with the object and determine if the amount of energy exceeds adefined threshold. For example, the energy detector may receiveinformation identifying the relative altitude (height) of the UAV anddetermine the kinetic energy of the UAV 100 at impact. For example, ifthe UAV 100 is 100 meters (h) above the object and loses power such thatit begins a free-fall from that height, the velocity (v) of the UAV 100just before impact will be approximately 44.27 meters/second (v=√{squareroot over (2gh)}, where g is gravity (9.81 m/s²)). If the mass of theUAV 100 is 25 kilograms, the kinetic energy just before impact will be24,500 joules, which will be approximately equal to the force at impact,depending on the object and its ability to absorb the impact withoutdamage to the object. The calculated force at impact and/or kineticenergy at impact may be used to determine the likelihood of damage to anobject with which the UAV may collide.

Based on the various data/information provided from the safetymonitoring system 103, the damage avoidance system 101 determines if therisk of damage to the object exceeds a damage risk threshold. The damagerisk threshold may vary according to particular needs, differentdetermined object types, etc. In some implementations, the damage riskthreshold may be exceeded if the distance measured between the objectand the UAV 100 is such that a possible impact from an uncontrolled ordegraded flight of the UAV may damage the object. In otherimplementations, the damage risk threshold may be exceeded if the safetymonitoring system 103 measures that the rate of descent of the UAV 100exceeds a predetermined velocity. As another example, the damage riskthreshold may be exceeded if the calculated kinetic energy at impactand/or the calculated force at impact exceeds a defined threshold. Asstill another example, if the object type is determined to be an animal,the damage risk threshold may be exceeded. Any combination ofmeasurements, UAV specifications, calculations and/or durability testinformation may be used by the damage avoidance system 101 to determinewhether the damage threshold has been, will be, or is predicted to beexceeded.

If the damage risk threshold is exceeded, the damage avoidance system101 activates the protection system 107, described below, which takessteps to reduce or substantially eliminate the damage to the object thatwould otherwise potentially be caused at impact.

In addition to determining whether a risk of damage exceeds a damagerisk threshold, the damage avoidance system 101 may utilize measurementsfrom the safety monitoring system 103 (e.g., distance, velocity,acceleration) to calculate and/or predict a time remaining until impactwith the object. The time remaining until impact may be used by theprotection system 107 to determine whether and/or when the reorientationelement 118 and/or the protection element 120 should be activated. Forexample, if the protection element is a parachute and the measuredorientation, motion and time until impact are such that the device willbe oriented with the protection element 120 positioned upward and awayfrom the object in time for deployment before impact, the protectionsystem 107 may not activate the reorientation element 118. However, ifthe data measurements indicate that the UAV 100 will not be reorientedin time to deploy the protection element 120, the protection system 107may activate the reorientation element 118 at a specific time, based onthe measurements, so that the UAV 100 is reoriented such that a sidewith a protection element 120 will be properly oriented with sufficienttime to deploy the protection element 120 and slow the rate of descentof the UAV 100.

The protection system 107 may include any number of components that workto reduce or eliminate the detected risk of damage to the object. Forexample, the protection system 107 may include an orientation detector116, a reorientation element 118 and a protection element 120. Theorientation detector 116 may be a stand-alone component or combinationof components that are designed to detect the orientation of the UAV100. For example, devices such as accelerometers or tilt sensors couldbe used. As another example, orientation detector 116 may be a cameraassociated with the UAV 100. For example, the camera can be located onthe top, bottom and/or sides of the UAV 100. The camera may be used todetermine whether the protection element 120 is oriented toward or awayfrom the object. As described below, this information may help theprotection system 107 determine what actions to take so that the UAV 100will be in a desired orientation at impact with the object and/or whenthe protection element 120 is deployed.

The reorientation element 118 may be any number of elements that canalter the orientation of the UAV 100. In general, the reorientationelement 118 may produce a force, alter a physical property or otherwisecreate a change in and/or alter the orientation of the UAV 100. Asdiscussed below with respect to FIGS. 7-9B, examples of thereorientation element 118 may be a gas expelled from a compressed gascartridge, an incompressible liquid (e.g., water) expelled from acartridge, a rotational modifier, a movable weight or other types ofdevices that can cause reorientation of the UAV 100, etc. An examplereorientation technique using a movable weight may be to relocate theposition of the power module 112 to alter or create a rotation of UAV100. Yet another technique may be to utilize actuators to causevibrations in the UAV 100 that cause UAV 100 to rotate in a desireddirection. These techniques may be used alone or in conjunction witheach other. Other techniques may be readily apparent to a person skilledin the relevant art. In one implementation, reorientation element 118and protection element 120 can be combined into a single element. Forexample, the same propulsion elements can be used to alter the deviceorientation as well as deploy the protection element 120, such as aparachute.

The protection element 120 may be any number of elements that helpprotect an object from damage due to impact by the UAV. In general, theprotection element 120 acts to absorb or alter the energy that wouldotherwise transfer to the object as a result of a collision between theobject and the UAV. The protection element 120 may be anenergy-absorbing material, a material that allows the kinetic energy ofUAV 100 to be dissipated over a greater time or area, a material thatreduces the kinetic energy of UAV 100 or other appropriate materials. Asdiscussed below with respect to FIGS. 2A-6, examples of the protectionelement 120 may be one or more of a parachute, an airbag, a propulsionelement, a spring, and an impact absorbing structure, among others.

In some implementations, the damage avoidance system 101 may utilize thepower module 112 of the UAV 100. In other implementations, the damageavoidance system 101 may include and/or utilize its own power moduleand/or have a backup power module available in the event the powermodule 112 of the UAV is inoperable.

In some implementations, the damage avoidance system 101 may beconfigured to utilize the propellers of the UAV to generate electricitythat is stored in one or more storage components (e.g., capacitors,batteries) and which may be used to initiate damage protection and/ordeploy a protection element, as discussed further below with respect toFIGS. 1C and 1D.

In some implementations, the damage avoidance system 101 may beconfigured to isolate or destroy the power module 112 prior to impactwith the object so that the power module 112 does not potentially igniteor explode at impact. For example, if the protection system 107 isactivated and it is determined that the UAV is high enough that thepower module can be isolated prior to impact, the protection system 107may short circuit the power module (e.g., by penetrating the wall of thepower module), causing it to deplete its energy prior to impact.

FIGS. 1C and 1D are circuit diagrams illustrating example deploymentcircuits for deploying the protection element 120, according to animplementation. If the UAV is rapidly descending toward an object, thepropellers may be allowed to freely rotate as the airflow from thedescent passes the blades of the propellers and the propeller motors maybe operated as generators. The free rotation of the propellers willcause the rotor of the motor to rotate around the stator of the motor.The electromagnets of the stator of the motor will generate alternatingcurrent (AC) in response to the permanent magnets of the rotor rotatingaround the stator. The deployment circuit 140 may be coupled to themotor, represented as the three-phase AC source 142 (FIG. 1C).

In the illustrated example, the three-phase AC source 142 (motor) iscoupled to a three-phase rectifier 144 that converts the AC to directcurrent (DC). The resulting DC may be provided to a DC-DC boostconverter 146 that increases the source voltage and reduces the sourcecurrent. The output from the DC-DC boost converter 146 is used to chargeone or more capacitors 148. The one or more capacitors are coupled to asilicon-controlled rectifier (SCR) 150. The SCR 150 provides a triggeror gate for energizing a solenoid 152. When the one or more capacitors148 become fully charged, the voltage rise on the gate of the SCR willcause the SCR to latch, thereby discharging the one or more capacitors148 into and activating the solenoid 152. The solenoid is then used todischarge the protection element 120.

FIG. 1D illustrates an alternative deployment circuit 160 for deployinga protection element 120, according to an implementation. Similar to thedeployment circuit 140, the AC from the motor, represented as thethree-phase AC source 162, is provided to a three-phase rectifier 164and the resulting DC voltage is stepped-up with a DC-DC boost converter166 to charge one or more capacitors 168. In this example, rather thanutilizing a SCR to control the triggering of the solenoid, the output ofthe three-phase rectifier 164 is coupled to a low-dropout (LDO)/bandgapgenerator 167 that provides a reference voltage to a change comparator169. The change comparator 169 compares the reference voltage from theLDO/bandgap generator 167 with the output from the one or morecapacitors 168. When the one or more capacitors 168 become fullycharged, the output voltage increases causing the change comparator 169to activate and provide current to the base of a bipolar junction (BJT)transistor 180. The current to the base of the BJT 180 causes the BJTtransistor 180 to become active, which results in the capacitor 168discharging into the solenoid 172, which discharges the protectionelement 120.

Utilizing a deployment circuit, such as the ones illustrated in FIGS. 1Cand 1D, there is no need for a power module and/or the damage avoidancesystem. Alternatively, such a configuration may be utilized as yetanother backup for protecting the UAV from damage. For example, thedamage avoidance system 101 may be configured as discussed herein andthe configuration of automatically deploying the protection element whena capacitor(s) fully charges may be utilized as a backup protectionsystem in the event the damage avoidance system is inoperable.

While the example deployment circuits 140, 160 utilize one or morecapacitors, in other implementations other components (e.g., batteries)may be used. Likewise, the solenoid may be a mechanical solenoid that isused to activate the discharge element (e.g., gas/liquid chamber,propellant) and deploy the protection element. In other implementations,the solenoid may be configured to electrically ignite a dischargeelement and cause the deployment of the protection element 120.

To control activation of a deployment circuit 140, 160, the connectionbetween the deployment circuit and the motor may be selectively enabled.For example, a hall sensor (not shown) may be used to monitor thedirection of rotation of the motor (and thus the propellers). When themotor is rotating in response to the motor driving the rotation of thepropellers in a first direction the deployment circuit is decoupled fromthe motor. However, when the hall sensor detects that the motor isrotating in a second direction, the deployment circuit is connected andcurrent generated by the free rotation of the propellers in the seconddirection is provided to the deployment circuit. In otherimplementations, any one of a passive resistor-capacitor (RC) dischargecircuit may be utilized that is triggered upon exceeding the duration ofthe first order discharge transient of the RC discharge circuit, asingle impulse/trigger LiPo voltage monitor, a low-powerinertial-measurement unit (IMU) data board, the system operabilitydetector 113, the energy detector 117, etc., may be used to activateand/or deactivate a deployment circuit, such as the deployment circuits140, 160 discussed herein.

FIG. 2A depicts a block diagram of a side view 200 of an UAV 100,according to an implementation. In the side view of the UAV illustratedin FIG. 2A, four motors 202 and propellers 204 are visible. In otherimplementations, additional or fewer motors 202 and/or propellers 204may be included in the UAV 100. In this example, the motors 202 may allbe mounted at 90 degrees with respect to the UAV 100. In an alternativeimplementation, the mountings of the motors may be adjustable and/or atdifferent angles.

Mounted to the top, or upper surface of the UAV 100 is a protectionelement 220. In this implementation, the protection element 220 includesa parachute 206 that may be deployed when the risk of damage to anobject exceeds a damage threshold. To speed deployment of the parachute,the parachute may be coupled to a deployment projectile 208. Forexample, the deployment projectile 208 may be a mass that is coupled tothe top of the canopy of the parachute 206, for example, with a tetheror other cord. When the deployment projectile 208 is deployed, asillustrated in FIG. 2B, it pulls the parachute 206 from the protectionelement 220 housing until the suspension lines 212 of the parachute 206are taut, thereby increasing the speed at which the canopy of theparachute 206 will fill with air, which will, in turn, slow the rate ofdescent of the UAV 100 and reduce the potential of damage to an objectwith which the UAV may impact. The deployment projectile 208 may bedischarged from the UAV 100 by igniting or releasing a propellant 210,such as gun powder, compressed gas (e.g., carbon dioxide, air),compressed water, solid-fuel rockets, etc. The propellant 210 may beelectrically ignited by the damage avoidance system. For example, adeployment circuit, such as the ones discussed above with respect toFIGS. 1C and 1D may be used to ignite the propellant 210. In otherimplementations, the deployment projectile may be deployed mechanicallythrough use of a solenoid, a spring, etc.

In some implementations, the propellant 210 and/or the container thatcontains the propellant may be utilized as the deployment projectile208. For example, the protection element 220 may include a gas or liquidcartridge that is attached to a top of the parachute 206 canopy with atether 207 and oriented such that the cartridge will deploy from the UAV100 when discharged. The force of the deployment and the weight of thecartridge will pull the parachute 206 from the protection element 220housing until the suspension lines 212 of the parachute 206 are taut andthe canopy can fill with air. In another example, a solid-fuel rocketmay be configured to operate as both the propellant 210 and thedeployment projectile 208.

In some implementations, the protection element 220 of the UAV 100 mayinclude one parachute. In other implementations, multiple parachutes maybe mounted on the same and/or different sides of the UAV 100. If thereare multiple parachutes coupled to the same side of the UAV 100, theymay all be configured to deploy if the risk of damage to the UAV exceedsa threshold. In comparison, in some implementations, there may be one ormore parachutes and corresponding deployment projectiles mounted to thetop of the UAV, one or more parachutes and corresponding deploymentprojectiles mounted to the bottom of the UAV, and/or one or moreparachutes and corresponding deployment projectiles mounted to each ofthe sides of the UAV. In such an implementation, rather than attemptingto re-orient the UAV to enable deployment of the parachute from the topof the UAV 100, the orientation of the UAV may be determined and theappropriate parachute(s) deployed.

In some implementations, the orientation of the deployment of aparachute may also be adjusted. For example, the orientation of the UAV100 may be determined, a parachute selected, and the orientation of theparachute and/or a deployment projectile coupled to the parachute may beadjusted so that it is deployed in an appropriate direction with respectto the object. Alternatively, or in addition thereto, a parachute may beattached to multiple deployment projectiles oriented in differentdirections. In such an implementation, a deployment projectile may bedetermined and deployed based on the orientation of the UAV 100.

In some implementations, rather than or in addition to utilizing adeployment projectile to deploy the parachute, the parachute 206 mayinclude one or more weights (not shown) secured around the perimeter ofthe canopy near the junction between the canopy and the suspensionlines. To deploy the parachute 206, the damage avoidance system 101 maycause the UAV 100 to rotate or alter its yaw at a rate sufficient togenerate enough centrifugal force on the weights to cause deployment ofthe parachute 206 from the protection element 220. The centrifugal forcepulling the weights from the protection element will aid in rapiddeployment of the parachute by opening the canopy and allowing it toquickly fill with air, thereby slowing the rate of the descent of theUAV 100.

In some implementations, the protection element 220 may include sidesthat form a cavity into which the parachute 206 is stored when not inuse. In implementations that utilize perimeter weights and centrifugalforce to deploy the parachute 206 from the protection element 220, thesides of the protection element 220 may be angled outward to aid in thedeployment of the weights by allowing the weights to slide up theinterior of the angled sides as the UAV 100 rotates. In otherimplementations, the sides may be configured to break or rotate out ofthe way when the parachute is to be deployed. Likewise, if theprotection element 220 includes a top, the top may be removed, rotatedor otherwise discharged to allow the parachute 206 to deploy.

FIG. 2C depicts a block diagram of a side view 200 of the UAV 100 with aprotection element deployed, according to an implementation. Continuingwith the above example, the protection element is a parachute 206 thathas deployed from the UAV to slow the rate of descent of the UAV 100. Bydeploying the parachute using a deployment projectile, the suspensionlines 212 quickly become taut and the canopy 214 of the parachute 206will quickly expand and fill with air, thereby slowing the rate ofdescent of the UAV.

In some implementations, as an alternative or in addition to aparachute, the protection element 220 may include an expandable membrane(e.g., balloon). In such an implementation, rather than utilizing adeployment projectile and a propellant, the protection element 220 mayinclude a gas chamber that includes a gas, such as hydrogen or helium,that is lighter than air that can be used to fill the expandablemembrane, thereby deploying it from the protection element and slowingor stopping the rate of descent of the UAV 100. The flexible membranemay be any of a variety of materials including, but not limited to,rubber, latex, polychloroprene, a nylon fabric, etc. When the risk ofdamage to an object exceeds the damage risk threshold, the gas chamberis released and the gas fills the flexible membrane.

FIGS. 3A-6 illustrate various other implementations of the protectionelement 120 (FIG. 1B). FIG. 3A illustrates an implementation of aprotection element 120 of the UAV 300 having an airbag 302. A deflatedairbag 302 may be embedded into the UAV 300. The airbag 302 may becoupled to a compressed gas cartridge 304. Upon detection by the damageavoidance system 101 that the risk of damage to an object exceeds adamage risk threshold, the protection system 107 may cause the airbag302 to deploy out of atop, bottom, and/or side of the UAV 300 prior toimpact with the object. The airbag 302 may be inflated by the compressedgas cartridge 304. For example, the gas cartridge may be a compressedair or carbon dioxide cartridge. In certain implementations, the airbag302 may be deployable from multiple sides of the UAV 300. Thus, theairbag 302 can be deployed from the side of the UAV 300 that is expectedto impact the object. Alternatively, there may be multiple airbags 302that are deployable to cover all or some of the UAV 300. In general, theairbag 302 should deploy at least on a side that will potentially impactthe object first.

FIG. 3B illustrates an implementation of the UAV 300 in which the airbag302 has been deployed as an inflated airbag 306. FIG. 3B shows theinflated airbag 306 along the bottom surface of the UAV 300. Theinflated airbag 306 provides a cushion along the bottom surface of theUAV 300 such that upon impact, the inflated airbag 306 reduces (oreliminates) the energy transferred to the object, thereby reducing oreliminating any damage to the object. The airbag may, in someimplementations, be deployed from another surface of the UAV 300 (aswell as more than one surface).

FIG. 4A illustrates an implementation of a protection element 120 of theUAV 400 having deployable air deflectors 402, or sails. In FIG. 4A, theair deflectors 402 are in a retracted position. The air deflectors 402may be fabricated of a flexible material, such as nylon, cloth, rubber,etc., and rolled or folded into a retracted position. The air deflectors402 may be coupled to a rail or guidance mechanism that can move alongthe rigid members 405 to extend the air deflector 402. For example, upondetection by the damage avoidance system 101 that the risk of damageexceeds a damage threshold, the protection system 107 may cause the airdeflectors 402 to deploy prior to impact. As illustrated, the airdeflectors 402 may be located at multiple positions on the UAV 400.

FIG. 4B illustrates an implementation of the UAV 400 in which the airdeflectors 402 have been deployed as air deflectors 404. The expandedair deflectors 404 provide air resistance to slow the rate of descent ofthe UAV, thereby reducing the force at impact. The air deflectors 404may be deployed by moving an extension arm 406 along a rail that iscoupled to the rigid members 405. The extension arm may be moved by amotor that pushes/pulls the extension arm 406 along the rails.Alternatively, or in addition thereto, the UAV 400 may rotate or alterits yaw at a rate sufficient to cause deployment of the air deflectors404 from the forces created by the rotation.

FIG. 5 illustrates an implementation of an UAV 500 having a protectionelement 120 that includes one or more propulsion elements 502.Propulsion elements 502 may operate to propel and/or expel a gas fromthe UAV 500 to reduce the speed of the UAV 500 as it travels toward anobject. A compressed gas cartridge, as described above, may be used as asource for the gas.

FIG. 6 illustrates an implementation of the UAV 600 having animplementation of the protection element 120 that includes one or moresprings 602. In one instance, one or more springs 602 are deployablefrom one or more side(s) or face(s) of the UAV 600 prior to impact inorder to absorb at least a portion of the impact energy to minimize orprevent damage to the object. In such an implementation, the UAV 600 maybe reoriented prior to impact such that deployed springs 602 aresubstantially perpendicular relative to the object with which the impactmay occur. In some implementations, one or more springs 602 may belocated within the body of the UAV 600 such that a portion of thehousing of the UAV 600 is physically separated from at least some of theinternal components within the UAV 600 prior to impact. This way, uponimpact, the housing of the UAV first impacts the object. As a result,the housing of the UAV, in combination with the spring(s) 602, preventsthe impact energy from transferring to the internal components of theUAV and reduces the forces transferred to the object.

FIG. 7 illustrates an implementation of an UAV 700 wherein thereorientation element 118 (FIG. 1B) includes one or more openings 702 inthe UAV 700. The UAV 700 may have more or fewer openings 702 than shownin FIG. 7. The openings 702 may extend completely through the UAV 700 orextend only part-way through the UAV 700. The openings 702 may also bemodifiable (e.g., a valve), fixed or any combination of modifiable andfixed openings.

In some implementations, the openings 702 may be used to reorient theUAV 700 while it is descending. The openings 702 may also provide theUAV 700 with the ability to alter its angular momentum to eitherincrease or decrease its rate of rotation. As will be discussed in moredetail below, altering the rate of rotation of the UAV 700 may allowprotection element 120 (FIG. 1B) to be in a position to protect anobject from damage caused by impact.

As an example of using openings 702 as a reorientation element 118, theopenings 702 in the UAV 700 may comprise a propulsion element to allowgas to be forced through the openings 702 in order to impart anadditional force to alter the orientation of the UAV 700. In thisimplementation, the openings 702 travel part-way through the UAV 700 sothat the gas can be expelled from a side or selectable portion of theUAV 700. For example, the UAV 700 may include one or more compressed gascartridges (not shown) and valves (not shown) that may be used tocontrol from which openings 702 the gas is expelled and the rate ofexpulsion from each cartridge. By selectively expelling gas throughcertain openings 702 and controlling the rate of gas expelled from eachopening, the angular momentum of the UAV 700 can be altered. The gas canbe used to increase or decrease the rate of rotation of the UAV 700 sothat, at the point of impact with the object, the UAV 700 is oriented sothat a side with a protection element 120 first impacts the object. Asdepicted in FIG. 7, gas can be forced through one opening 702 on oneside (e.g., top) of the UAV 700, and gas can be forced through anotheropening 702 on the opposite side (e.g., bottom) of the UAV 700. Thisallows extra force to increase or decrease the rate of rotation of theUAV 700. In some implementations, the openings 702 may be adjustable inorder to expel the gas in one or more directions.

According to one implementation, as the UAV 700 is moving toward anobject, it may be desirable to alter the orientation of the UAV 700 bythirty degrees so that the bottom of the UAV 700 first impacts theobject and/or so that the propellers of the UAV are away from theobject. Utilizing the damage avoidance system 101, it is determined thatadditional angular momentum is required in order to achieve the desiredorientation before impact with the object. Accordingly, the damageavoidance system 101 causes the reorientation element 118 to expel gasthrough one or more openings 702 to provide additional angular momentumto alter the orientation of UAV 700 so that a thirty degree rotation canbe achieved prior to impact.

As another implementation, the openings 702 in the UAV 700 may not useany propulsion element at all. In one implementation, the openings 702may extend through the UAV 700 and are modifiable from either side ofthe UAV 700. For example, one or more openings 702 can be selectivelyopened or closed to alter the air resistance on a side of the UAV 700. Acontrol element such as a solenoid and/or motor (not shown) in the UAV700 may cause a cover to partially or completely block one or more ofthe openings 702, thereby altering the resistance on a side of the UAV700. By increasing or decreasing the air resistance, the orientation ofUAV 700 can be altered.

FIGS. 8A, 8B and 8C illustrate an implementation of an UAV 800 where thereorientation element 118 (FIG. 1B) includes a rotational modifier 802.The rotational modifier 802 may be any number of components that canmodify the rotation of the UAV 800. Modifying the rotation of the UAV800 may allow a desired side of the UAV 800 to first impact the objectand/or to orient the UAV 800 so the propellers are away from the object.

An illustrative rotational modifier 802 may be an actuator or other typeof vibration mechanism, such as a motor 804 (FIG. 8B) attached to anoffset weight. The vibration mechanism can rotate to a selected positionand then vibrate on a side of the UAV 800 to provide impulses in aparticular direction to increase or decrease rotation of the UAV 800. Insome implementations, the rotational modifier 802 can be a gyroscope.For example, a gyroscope can be designed to increase or decrease therate of rotation of the UAV 800. In operation, when the damage avoidancesystem 101 determines that, based on the current rate of rotation of theUAV 800, a side of the UAV 800 with the protection element 120 will notbe properly oriented, the damage avoidance system 101 may cause theprotection system 107 to activate a gyroscope (reorientation element118) to reorient the UAV 800 to a desired orientation.

While in some implementations the rotational modifier 802 is operable torotate an offset weight such that it creates a substantially continuousvibration in the device, in other implementations, the offset weight canbe rotated into one or more alternative positions from its normalposition in order to alter the center of mass of UAV 800. For example,FIG. 8B illustrates an implementation of reorientation element 118 (FIG.1B) that includes the rotational modifier 802 of FIG. 8A in one possiblealternative position. As depicted, the rotational modifier 802 isoperable to rotate offset weight 806 about axis 808. The position of theoffset weight 806 depicted in solid lines can denote a position in whichthe offset weight 806 is in a normal position, while the positiondepicted in hashed lines depicts the offset weight 806 in a first offsetposition. Similarly, FIG. 8C illustrates an implementation ofreorientation element 118 that includes the rotational modifier 802 ofFIG. 8A in a second possible alternative position. Here, the positiondepicted in solid lines again denotes the position in which the offsetweight 806 is in a normal position, while the position depicted inhashed lines depicts the offset weight 806 in a second offset position.Accordingly, the center of mass of UAV 800 is altered as needed bymoving the offset weight 806 into these example alternative positions.

FIGS. 9A and 9B illustrate an implementation of a reorientation element118 incorporated into an UAV that includes a movable weight 902. FIG. 9Aillustrates a compartment 904 of the UAV that includes the reorientationelement 118. The compartment 904 may be internal to the UAV or part ofthe external housing of the UAV. A movable weight 902, when moved,alters the center of gravity of the UAV 900 to cause a change in therate or direction of rotation of the UAV 900.

In one implementation, the movable weight 902 is a relatively heavycomponent of the UAV 900, such as a power module 112 (FIG. 1A). Byaltering the location of the movable weight 902 within the compartment904, the center of gravity of the UAV 900 is altered. Using a powermodule 112 as the movable weight 902 to change the center of gravity ofthe UAV 900, as well as providing power to the UAV 900, allows the powermodule to serve multiple purposes and eliminates the need to have aseparate movable weight 902 in the UAV 900.

FIG. 9A illustrates that, according to some implementations, the movableweight 902 may be placed on rails 906 within compartment 904 in the UAV900. The movable weight 902 may be held in place by various objects,such as retractable pins 908, that can releasably control an object inplace along the rails 906. When it is desired to relocate the movableweight 902 within compartment 904 in order to change the center ofgravity of the UAV 900, one set of pins 908 may be withdrawn to allowthe movable weight 902 to slide along the rails 906 to a new locationwithin the UAV 900. Alternatively, or in addition to the rails 906, amotor (not shown) can cause the movable weight 902 to move along therails 906 to a desired location.

Although FIG. 9A illustrates that the movable weight 902 has only onedegree of freedom along the rails 906 (as shown by arrow A-A), FIG. 9Billustrates that the movable weight 902 may be able to move inadditional degrees of freedom (e.g. along any number of axes, includingthe X, Y and Z axes) in other implementations. At some time afterrecovery of the UAV 900, the movable weight 902 can be returned to itsoriginal position and re-secured on the rails 906. In yet otherimplementations, the movable weight 902 is an example of an ejectableelement that can be completely ejected from the UAV 900. This ejectioncan serve to change the center of mass of the UAV 900, cause the UAV 900to have a lower mass at impact and/or alter the orientation of the UAV900 from the force of the ejection of the movable weight 902 (e.g. fromsprings or other mechanisms operable to eject the movable weight 902from the UAV 900). The ejectable element can include one or morerelatively heavy components of the UAV 900. Alternatively, the ejectableelement may be the deployment projectile 208 (FIG. 2A) discussed above.

While the above examples discuss techniques for avoiding and/or reducingdamage to an object that may be impacted by a UAV, other avoidancemeasures may also be provided. For example, in addition to deploying aprotection element to reduce a potential for damage to an object atimpact, an audible and/or visual output may be generated to alert anobject to a potential impact. For example, if the damage avoidancesystem is activated, in addition to deploying the protection element, anaudible tone or warning message may be transmitted from the UAV to alertan object to the potential impact from the UAV. Likewise, a notificationor alert may be transmitted from the UAV to the UAV management systemand/or other UAVs to notify the UAV management system and/or other UAVsthat the damage avoidance system has been activated. The notificationmay include, among other information, the location of the UAV, the timeat which the damage avoidance system was activated, the reason(s) forthe activation, etc.

FIG. 10 depicts a block diagram of an UAV network 1000 that includesUAVs 100, delivery locations 1003, relay locations 1002, materialshandling facilities 1004 and remote computing resources 1010, accordingto an implementation. In addition, one or more fixed positiontransmitters 1005 may be included in the environment that transmit fixedposition information (e.g., geographic coordinates), weather,information from other UAVs, information from the UAV management system,etc. The fixed position transmitters may be included at any known, fixedlocation. For example, the fixed position transmitters may be includedon a materials handling facility(s) 1004, relay location(s) 1002,delivery location(s) 1003, on cellular towers (not shown), on buildings,on landing areas, or at any other known location.

Each of the UAVs 100, delivery locations 1003, relay locations 1002,materials handling facilities 1004 and/or remote computing resources1010 may be configured to communicate with one another. For example, theUAVs 100 may be configured to form a wireless mesh network that utilizesWi-Fi or another wireless means of communication, each UAV communicatingwith other UAVs within wireless range. In other implementations, theUAVs 100, UAV management system 1026, materials handling facilities1004, relay locations 1002 and/or the delivery locations 1003 mayutilize existing wireless networks (e.g., cellular, Wi-Fi, satellite) tofacilitate communication. Likewise, the remote computing resources 1010,materials handling facilities 1004, delivery locations 1003 and/or relaylocations 1002 may also be included in the wireless mesh network. Insome implementations, one or more of the remote computing resources1010, materials handling facilities 1004, delivery locations 1003 and/orrelay locations 1002 may also communicate with each other via anothernetwork (wired and/or wireless), such as the Internet.

The remote computing resources 1010 may form a portion of anetwork-accessible computing platform implemented as a computinginfrastructure of processors, storage, software, data access, and othercomponents that is maintained and accessible via a network, such as themesh network and/or another wireless or wired network (e.g., theInternet). As illustrated, the remote computing resources 1010 mayinclude one or more servers, such as servers 1020(1), 1020(2), . . . ,1020(N). These servers 1020(1)-(N) may be arranged in any number ofways, such as server farms, stacks, and the like that are commonly usedin data centers. Furthermore, the servers 1020(1)-(N) may include one ormore processors 1022 and memory 1024 which may store a UAV managementsystem 1026.

The UAV management system 1026 may be configured, for example, tocommunicate with the delivery locations 1003, UAVs 100, materialshandling facilities 1004, and/or relay locations 1002. As an example,position information for each UAV 100 may be determined and shared amongUAVs. Each UAV may periodically transmit, for example, automaticdependent surveillance-broadcast (“ADS-B”) information to other UAVs inthe network. When information, such as ADS-B information, is sent to orfrom an UAV, the information may include an identifier for the UAV andeach UAV may act as a node within the network, forwarding theinformation until it is received by the intended UAV. For example, theUAV management system 1026 may send a message to UAV 100-6 bytransmitting the information and the identifier of the intendedreceiving UAV to one or more of UAVs 100-1, 100-2, 100-3, 100-4 that arein wireless communication with the UAV management system 1026. Eachreceiving UAV will process the identifier to determine if it is theintended recipient and then forward the information to one or more otherUAVs that are in communication with the UAV. For example, UAV 100-2 mayforward the message and the identification of the intended receiving UAVto UAV 100-1, 100-3 and 100-5. In such an example, because 100-3 hasalready received and forwarded the message, it may discard the messagewithout forwarding it again, thereby reducing load on the mesh network1000. The other UAVs, upon receiving the message, may determine thatthey are not the intended recipients and forward it on to other nodes.This process may continue until the message reaches the intendedrecipient.

In some implementations, if an UAV loses communication with other UAVsvia the wireless mesh network, it may activate another wirelesscommunication path to regain connection. For example, if an UAV cannotcommunicate with any other UAVs via the mesh network 1000, it mayactivate a cellular and/or satellite communication path to obtaincommunication information from the UAV management system 1026, materialshandling facility 1004, relay location 1002 and/or a delivery location1003. If the UAV still cannot regain communication and/or if it does notinclude an alternative communication component, it may automatically andautonomously navigate toward a designated location (e.g., a nearbymaterials handling facility 1004, relay location 1002 and/or deliverylocation 1003).

The wireless mesh network 1000 may be used to provide communicationbetween UAVs (e.g., to share weather information including wind speedsand directions, location information, routing information, landingareas), the UAV management system 1026, materials handling facilities1004, delivery locations 1003 and/or relay locations 1002. In someimplementations, if an UAV 100 initiates a protection procedure and/ordeploys a protection element, it may communicate to the other componentsof the UAV network 1000 that it has initiated a protection procedureand/or deployed a protection element, and may also provide otherinformation. For example, an UAV 100 may provide location information, abeacon signal, and/or other information to aid in the recovery of theUAV 100 in the event the UAV impacts an object.

In addition, in some implementations, the wireless mesh network may beused to deliver content and/or other information to other computingresources, such as personal computers, electronic book reading devices,audio players, mobile telephones, tablets, desktops, laptops, etc. Forexample, the mesh network may be used to deliver electronic book contentto electronic book reading devices of customers.

FIG. 11 depicts a flow diagram of an example process 1100 for deployinga protection element, according to an implementation. This process, andeach process described herein, may be implemented by the architecturesdescribed herein or by other architectures. The process is illustratedas a collection of blocks in a logical flow. Some of the blocksrepresent operations that can be implemented in hardware, software, or acombination thereof. In the context of software, the blocks representcomputer-executable instructions stored on one or more computer readablemedia that, when executed by one or more processors, perform the recitedoperations. Generally, computer-executable instructions includeroutines, programs, objects, components, data structures, and the likethat perform particular functions or implement particular abstract datatypes.

The computer readable media may include non-transitory computer readablestorage media, which may include hard drives, floppy diskettes, opticaldisks, CD-ROMs, DVDs, read-only memories (ROMs), random access memories(RAMs), EPROMs, EEPROMs, flash memory, magnetic or optical cards,solid-state memory devices, or other types of storage media suitable forstoring electronic instructions. In addition, in some implementations,the computer readable media may include a transitory computer readablesignal (in compressed or uncompressed form). Examples of computerreadable signals, whether modulated using a carrier or not, include, butare not limited to, signals that a computer system hosting or running acomputer program can be configured to access, including signalsdownloaded through the Internet or other networks. Finally, the order inwhich the operations are described is not intended to be construed as alimitation, and any number of the described operations can be combinedin any order and/or in parallel to implement the process. Additionally,one or more of the operations may be considered optional and/or notutilized with other operations.

The example process 1100 begins by detecting a loss of control of theUAV (e.g., the UAV is in an uncontrolled descent, is not following theflight path, has lost power, etc.), as in 1102. In response to detectinga loss of control of the UAV, the propellers may be disengaged andallowed to freely rotate in response to the wind passing through thepropellers, as in 1104. By allowing the propellers to freely rotate, thekinetic energy of the UAV descending toward the ground can be used togenerate energy that may be stored, as in 1106. For example, thegenerated energy may be stored in one or more capacitors, power modules,etc.

In addition to storing generated energy, a determination may be made asto whether the amount of stored energy exceeds a threshold, as in 1108.For example, as discussed above, a backup protective measure may includeautomatically initiating the protective element in response to acapacitor becoming fully charged (threshold) from energy generated fromthe freely rotating propellers. In other implementations, decision block1108 may be controlled and/or replaced by the damage avoidance system101 (FIG. 1B) deciding whether to initiate the protection element.

If it is determined that the stored energy does not exceed a threshold(e.g., a capacity of the one or more capacitors), or if the damageavoidance system determines not to initiate the protection element, theexample process 1100 returns to block 1106 and continues. However, ifthe stored energy does exceed the threshold and/or the damage avoidancesystem initiates the protection element, the protection element isdeployed, as in 1110. For example, a solenoid, mechanical actuator,discharge element, etc., may be energized or activated by a discharge ofthe stored energy to deploy any of the protection elements discussedabove to reduce a risk of damage to an object with which the UAV maycollide.

FIG. 12 is a flowchart illustrating a method 1200 executed by damageavoidance system 101 for protecting an object from potential damageusing a safety monitoring system 103 and a protection system 107, asdescribed above. At step 1202, damage avoidance system 101 determines arisk of potential damage to an object from an impact by the UAV 100. Insome implementations, damage avoidance system 101 periodically makesthis determination. In other implementations, damage avoidance system101 continuously (e.g., real-time) makes this determination. Forexample, damage avoidance system 101 may utilize one or more of thedistance detector 109, motion detector 111, system operability detector113 and/or object type detector 115 to determine the risk of potentialdamage to an object if impacted by the UAV 100. Damage avoidance system101 may weigh the information provided by each detector in the safetymonitoring system 103 differently when assessing a risk of potentialdamage.

At step 1204, the damage avoidance system 101 determines whether a riskof potential damage to an object exceeds a damage risk threshold. If thedamage avoidance system 101 determines that a risk of damage does notexceed a damage risk threshold, the example process 1200 returns to step1202. At a time after damage avoidance system 101 determines that a riskof damage to an object resulting from an impact by the UAV 100 exceeds adamage risk threshold, at step 1206 damage avoidance system 101 alters,if necessary, the orientation of the UAV 100. For example, iforientation detector 116 determines that the UAV 100 is already in adesired orientation, then the UAV 100 is not reoriented prior to impact.If reorientation of the UAV 100 is required, reorientation element 118alters the orientation of the UAV 100 one or more times prior to impactuntil the protection element 120 is positioned so that it can bedeployed in a manner that will reduce or eliminate damage to the UAVcaused by the impact. At step 1208, the protection element 120 may bedeployed. The protection element 120 may be deployed before, during orafter the reorientation of the UAV 100.

While the above examples discuss autonomous engagement of the damageavoidance system and autonomous deployment of a protection element, inother implementations, the damage avoidance system and/or protectionelement deployment may be semi-autonomous or manual. For example, any ofthe routines or damage avoidance system activations may include a humanoperator that is notified, authorizes and/or activates the damageavoidance system or deploys the protection element. In otherimplementations, if the UAV is under manual control, the operatorcontrolling the UAV may activate the damage avoidance system and/ordeploy the protection element.

FIG. 13 is a block diagram illustrating an example UAV control system110 of the UAV 100. In various examples, the block diagram may beillustrative of one or more aspects of the UAV control system 110 thatmay be used to implement the various systems and methods discussedabove. In the illustrated implementation, the UAV control system 110includes one or more processors 1302, coupled to a non-transitorycomputer readable storage medium 1320 via an input/output (I/O)interface 1310. The UAV control system 110 may also include a propellermotor controller 1304, power supply module 1306 and/or a navigationsystem 1308. The UAV control system 110 further includes an inventoryengagement mechanism controller 1312, a network interface 1316, and oneor more input/output devices 1318.

In some implementations, the UAV control system 110 may include thedamage avoidance system 101, discussed above. In such an implementation,the UAV control system 110 and the damage avoidance system 101 mayutilize one or more common sensors, memories, data stores, communicationcomponents, etc. However, in other implementations, as discussed herein,the UAV control system 110 and the damage avoidance system 101 may beseparate systems that utilize some or all of their own components and/orpower modules. Separating the damage avoidance system 101 from the UAVcontrol system 110 may provide additional redundancy and operability inthe event of a failure.

In various implementations, the UAV control system 110 may be auniprocessor system including one processor 1302, or a multiprocessorsystem including several processors 1302 (e.g., two, four, eight, oranother suitable number). The processor(s) 1302 may be any suitableprocessor capable of executing instructions. For example, in variousimplementations, the processor(s) 1302 may be general-purpose orembedded processors implementing any of a variety of instruction setarchitectures (ISAs), such as the x86, PowerPC, SPARC, or MIPS ISAs, orany other suitable ISA. In multiprocessor systems, each processor(s)1302 may commonly, but not necessarily, implement the same ISA.

The non-transitory computer readable storage medium 1320 may beconfigured to store executable instructions, data, flight paths and/ordata items accessible by the processor(s) 1302. In variousimplementations, the non-transitory computer readable storage medium1320 may be implemented using any suitable memory technology, such asstatic random access memory (SRAM), synchronous dynamic RAM (SDRAM),nonvolatile/Flash-type memory, or any other type of memory. In theillustrated implementation, program instructions and data implementingdesired functions, such as those described above, are shown storedwithin the non-transitory computer readable storage medium 1320 asprogram instructions 1322, data storage 1324 and flight path data 1326,respectively. In other implementations, program instructions, dataand/or flight paths may be received, sent or stored upon different typesof computer-accessible media, such as non-transitory media, or onsimilar media separate from the non-transitory computer readable storagemedium 1320 or the UAV control system 110. Generally speaking, anon-transitory, computer readable storage medium may include storagemedia or memory media, such as magnetic or optical media, e.g., disk orCD/DVD-ROM, coupled to the UAV control system 110 via the I/O interface1310. Program instructions and data stored via a non-transitory computerreadable medium may be transmitted by transmission media or signals,such as electrical, electromagnetic, or digital signals, which may beconveyed via a communication medium such as a network and/or a wirelesslink, such as may be implemented via the network interface 1316.

In one implementation, the I/O interface 1310 may be configured tocoordinate I/O traffic between the processor(s) 1302, the non-transitorycomputer readable storage medium 1320, and any peripheral devices, thenetwork interface or other peripheral interfaces, such as input/outputdevices 1318. In some implementations, the I/O interface 1310 mayperform any necessary protocol, timing or other data transformations toconvert data signals from one component (e.g., non-transitory computerreadable storage medium 1320) into a format suitable for use by anothercomponent (e.g., processor(s) 1302). In some implementations, the I/Ointerface 1310 may include support for devices attached through varioustypes of peripheral buses, such as a variant of the Peripheral ComponentInterconnect (PCI) bus standard or the Universal Serial Bus (USB)standard, for example. In some implementations, the function of the I/Ointerface 1310 may be split into two or more separate components, suchas a north bridge and a south bridge, for example. Also, in someimplementations, some or all of the functionality of the I/O interface1310, such as an interface to the non-transitory computer readablestorage medium 1320, may be incorporated directly into the processor(s)1302.

The propeller motor(s) controller 1304 communicates with the navigationsystem 1308 and adjusts the power of each propeller motor to guide theUAV along a determined flight path. As described above, in someimplementations, one or more of the propellers and propeller motors maybe used to generate energy resulting from an uncontrolled descent of theUAV. In various implementations, such energy generation procedures maydictate changes to the operation of the selected propeller motors. Forexample, electricity may no longer be supplied to the associatedpropeller motors, the angles of the motor mounts may be adjusted, and/orany energy generated by the propeller motors may be routed for variousfunctions (e.g., recharging one or more power modules, power a sensor,power the damage avoidance system 101, deploy a protection element,charge a capacitor, etc.)

The power supply module 1306 may control the charging and any switchingfunctions associated with one or more power modules (e.g., batteries) ofthe UAV. The navigation system 1308 may include a GPS or other similarsystem that can be used to navigate the UAV to and/or from a location.The inventory engagement mechanism controller 1312 communicates with themotor(s) (e.g., a servo motor) used to engage and/or disengageinventory. For example, when the UAV is positioned over a level surfaceat a delivery location, the inventory engagement mechanism controller1312 may provide an instruction to a motor that controls the inventoryengagement mechanism to release the inventory.

The network interface 1316 may be configured to allow data to beexchanged between the UAV control system 110, other devices attached toa network, such as other computer systems, and/or with UAV controlsystems of other UAVs. For example, the network interface 1316 mayenable wireless communication between numerous UAVs. In variousimplementations, the network interface 1316 may support communicationvia wireless general data networks, such as a Wi-Fi network. Forexample, the network interface 1316 may support communication viatelecommunications networks, such as cellular communication networks,satellite networks, and the like.

Input/output devices 1318 may, in some implementations, include one ormore displays, image capture devices, thermal sensors, infrared sensors,time of flight sensors, accelerometers, pressure sensors, weathersensors, airflow sensors, etc. Multiple input/output devices 1318 may bepresent and controlled by the UAV control system 110. One or more ofthese sensors may be utilized to assist in landings as well as avoidingobstacles during flight. In some implementations, the one or moresensors may be utilized by the damage avoidance system 101. However, inother implementations, the sensors of the damage avoidance system 101and the UAV control system 110 may be separate.

As shown in FIG. 13, the memory may include program instructions 1322which may be configured to implement the example processes and/orsub-processes described above. The data storage 1324 may include variousdata stores for maintaining data items that may be provided fordetermining flight paths, retrieving inventory, landing, identifying alevel surface for disengaging inventory, etc. Likewise, the damageavoidance system may include program instructions which may beconfigured to implement one or more of the example processes and/orsub-processes described above.

In various implementations, the parameter values and other dataillustrated herein as being included in one or more data stores may becombined with other information not described or may be partitioneddifferently into more, fewer, or different data structures. In someimplementations, data stores may be physically located in one memory ormay be distributed among two or more memories.

Those skilled in the art will appreciate that the UAV control system 110is merely illustrative and is not intended to limit the scope of thepresent disclosure. In particular, the computing system and devices mayinclude any combination of hardware or software that can perform theindicated functions, including computers, network devices, internetappliances, PDAs, wireless phones, pagers, etc. The UAV control system110 may also be connected to other devices that are not illustrated, orinstead may operate as a stand-alone system. In addition, thefunctionality provided by the illustrated components may, in someimplementations, be combined in fewer components or distributed inadditional components. Similarly, in some implementations, thefunctionality of some of the illustrated components may not be providedand/or other additional functionality may be available.

Those skilled in the art will also appreciate that, while various itemsare illustrated as being stored in memory or storage while being used,these items or portions of them may be transferred between memory andother storage devices for purposes of memory management and dataintegrity. Alternatively, in other implementations, some or all of thesoftware components may execute in memory on another device andcommunicate with the illustrated UAV control system 110 and/or thedamage avoidance system 101. Some or all of the system components ordata structures may also be stored (e.g., as instructions or structureddata) on a non-transitory, computer-accessible medium or a portablearticle to be read by an appropriate drive, various examples of whichare described above. In some implementations, instructions stored on acomputer-accessible medium separate from the UAV control system 110and/or the damage avoidance system 101 may be transmitted to the UAVcontrol system 110 and/or the damage avoidance system 101 viatransmission media or signals, such as electrical, electromagnetic, ordigital signals, conveyed via a communication medium such as a wirelesslink. Various implementations may further include receiving, sending orstoring instructions and/or data implemented in accordance with theforegoing description upon a computer-accessible medium. Accordingly,the techniques described herein may be practiced with other UAV controlsystem configurations.

FIG. 14 is a pictorial diagram of an illustrative implementation of aserver system, such as the server system 1020, that may be used in theimplementations described herein. The server system 1020 may include aprocessor 1400, such as one or more redundant processors, a videodisplay adapter 1402, a disk drive 1404, an input/output interface 1406,a network interface 1408, and a memory 1412. The processor 1400, thevideo display adapter 1402, the disk drive 1404, the input/outputinterface 1406, the network interface 1408, and the memory 1412 may becommunicatively coupled to each other by a communication bus 1410.

The video display adapter 1402 provides display signals to a localdisplay (not shown in FIG. 14) permitting an operator of the serversystem 1020 to monitor and configure operation of the server system1020. The input/output interface 1406 likewise communicates withexternal input/output devices not shown in FIG. 14, such as a mouse,keyboard, scanner, or other input and output devices that can beoperated by an operator of the server system 1020. The network interface1408 includes hardware, software, or any combination thereof, tocommunicate with other computing devices. For example, the networkinterface 1408 may be configured to provide communications between theserver system 1020 and other computing devices, such as an UAV,materials handling facility, relay location and/or a delivery location,as shown in FIG. 10.

The memory 1412 generally comprises random access memory (RAM),read-only memory (ROM), flash memory, and/or other volatile or permanentmemory. The memory 1412 is shown storing an operating system 1414 forcontrolling the operation of the server system 1020. A binaryinput/output system (BIOS) 1416 for controlling the low-level operationof the server system 1020 is also stored in the memory 1412.

The memory 1412 additionally stores program code and data for providingnetwork services to the UAV management system 1026. Accordingly, thememory 1412 may store a browser application 1418. The browserapplication 1418 comprises computer executable instructions that, whenexecuted by the processor 1400, generate or otherwise obtainconfigurable markup documents such as Web pages. The browser application1418 communicates with a data store manager application 1420 tofacilitate data exchange between the UAV data store 1422 and/or otherdata stores.

As used herein, the term “data store” refers to any device orcombination of devices capable of storing, accessing and retrievingdata, which may include any combination and number of data servers,databases, data storage devices and data storage media, in any standard,distributed or clustered environment. The server system 1020 can includeany appropriate hardware and software for integrating with the UAV datastore 1422 as needed to execute aspects of one or more applications forthe UAV management system, UAVs, materials handling facilities, deliverylocations, and/or relay locations.

The data store 1422 can include several separate data tables, databasesor other data storage mechanisms and media for storing data relating toa particular aspect. For example, the data store 1422 illustratedincludes UAV information, weather information, wind speeds anddirections, flight path information, source location information,destination location information, etc., which can be used to generateand deliver information to the UAV management system 1026, materialshandling facilities, delivery locations, UAVs, relay locations, and/orusers. It should be understood that there can be many other aspects thatmay be stored in the UAV data store 1422. The data stores 1422 areoperable, through logic associated therewith, to receive instructionsfrom the server system 1020 and obtain, update or otherwise process datain response thereto.

The memory 1412 may also include the UAV management system 1026,discussed above. The UAV management system 1026 may be executable by theprocessor 1400 to implement one or more of the functions of the serversystem 1020. In one implementation, the UAV management system 1026 mayrepresent instructions embodied in one or more software programs storedin the memory 1412. In another implementation, the UAV management system1026 can represent hardware, software instructions, or a combinationthereof.

The server system 1020, in one implementation, is a distributedenvironment utilizing several computer systems and components that areinterconnected via communication links, using one or more computernetworks or direct connections. However, it will be appreciated by thoseof ordinary skill in the art that such a system could operate equallywell in a system having fewer or a greater number of components than areillustrated in FIG. 14. Thus, the depiction in FIG. 14 should be takenas being illustrative in nature and not limiting to the scope of thedisclosure.

Those skilled in the art will appreciate that, in some implementations,the functionality provided by the processes and systems discussed abovemay be provided in alternative ways, such as being split among moresoftware modules or routines or consolidated into fewer modules orroutines. Similarly, in some implementations, illustrated processes andsystems may provide more or less functionality than is described, suchas when other illustrated processes instead lack or include suchfunctionality respectively, or when the amount of functionality that isprovided is altered. In addition, while various operations may beillustrated as being performed in a particular manner (e.g., in serialor in parallel) and/or in a particular order, those skilled in the artwill appreciate that, in other implementations, the operations may beperformed in other orders and in other manners. Those skilled in the artwill also appreciate that the data structures discussed above may bestructured in different manners, such as by having a single datastructure split into multiple data structures or by having multiple datastructures consolidated into a single data structure. Similarly, in someimplementations, illustrated data structures may store more or lessinformation than is described, such as when other illustrated datastructures instead lack or include such information respectively, orwhen the amount or types of information that is stored is altered. Thevarious methods and systems as illustrated in the figures and describedherein represent example implementations. The methods and systems may beimplemented in software, hardware, or a combination thereof in otherimplementations. Similarly, the order of any method may be changed andvarious elements may be added, reordered, combined, omitted, modified,etc., in other implementations.

From the foregoing, it will be appreciated that, although specificimplementations have been described herein for purposes of illustration,various modifications may be made without deviating from the spirit andscope of the appended claims and the elements recited therein. Inaddition, while certain aspects are presented below in certain claimforms, the inventors contemplate the various aspects in any availableclaim form. For example, while only some aspects may currently berecited as being embodied in a computer readable storage medium, otheraspects may likewise be so embodied. Various modifications and changesmay be made as would be obvious to a person skilled in the art havingthe benefit of this disclosure. It is intended to embrace all suchmodifications and changes and, accordingly, the above description is tobe regarded in an illustrative rather than a restrictive sense.

What is claimed is:
 1. A computer-implemented method, comprising: undercontrol of one or more computing systems configured with executableinstructions, determining a risk of damage resulting from an impactbetween an unmanned aerial vehicle and an object; determining that therisk of damage exceeds a threshold; determining an orientation of theunmanned aerial vehicle relative to the object; selecting a protectionelement, from a plurality of protection elements, for deployment basedat least in part on the determined orientation; and deploying from theunmanned aerial vehicle, prior to the impact, the protection elementconfigured to reduce a damage to at least one of the object or theunmanned aerial vehicle caused by the impact between the unmanned aerialvehicle and the object.
 2. The computer-implemented method of claim 1,further comprising: altering the orientation of the unmanned aerialvehicle to position the protection element so that deployment of theprotection element will reduce the damage to at least one of the objector the unmanned aerial vehicle.
 3. The computer-implemented method ofclaim 2, wherein the unmanned aerial vehicle is reoriented to positionthe protection element between a body of the unmanned aerial vehicle andthe object at impact.
 4. The computer-implemented method of claim 2,wherein the unmanned aerial vehicle is reoriented to position a body ofthe unmanned aerial vehicle between the protection element and theobject so that the protection element is deployed away from the object.5. The computer-implemented method of claim 2, wherein the orientationof the unmanned aerial vehicle is altered using a reorientation element,wherein the reorientation element includes at least one of a propulsionelement, a movable weight, an actuator, a gyroscope or a modifiableopening.
 6. The computer-implemented method of claim 1, wherein the riskof damage is determined based at least in part on a kinetic energy ofthe unmanned aerial vehicle at impact with the object, a velocity of theunmanned aerial vehicle, or a distance between the unmanned aerialvehicle and the object.
 7. An unmanned aerial vehicle, comprising: abody; a propeller; a safety monitoring system configured to detect arisk of damage to an object resulting from an impact between theunmanned aerial vehicle and the object; and a protection systemconfigured to determine an orientation of the unmanned aerial vehiclerelative to the object, select a protection element, from a plurality ofprotection elements, for deployment based at least in part on thedetermined orientation, and deploy the protection element prior to theimpact between the unmanned aerial vehicle and the object.
 8. Theunmanned aerial vehicle of claim 7, wherein the safety monitoring systemincludes at least one of a distance detector configured to measure adistance between the unmanned aerial vehicle and the object, a motiondetector configured to measure a motion of the unmanned aerial vehicle,a system operability detector configured to monitor an operability of atleast one component of the unmanned aerial vehicle, an object typedetector configured to determine a type of the object, or an energydetector configured to determine a kinetic energy of the unmanned aerialvehicle at an impact with the object.
 9. The unmanned aerial vehicle ofclaim 7, wherein the plurality of protection elements include at leastone of a parachute, an airbag, a propulsion element, or a spring. 10.The unmanned aerial vehicle of claim 7, further comprising: areorientation element configured to reorient the unmanned aerial vehicleto allow deployment of the protection element in an intended directionwith respect to the object.
 11. The unmanned aerial vehicle of claim 10,wherein the reorientation element is at least one of a compressed gascartridge configured to expel gas from the cartridge to cause areorientation of the unmanned aerial vehicle, a liquid filled cartridgeconfigured to expel an incompressible liquid from the cartridge to causea reorientation of the unmanned aerial vehicle, a rotational modifier,or a movable weight that may be repositioned with respect to the body ofthe unmanned aerial vehicle and cause a reorientation of the unmannedaerial vehicle.
 12. The unmanned aerial vehicle of claim 7, wherein theprotection element includes: a parachute; and a deployment projectilecoupled to the parachute and configured to be discharged from theprotection element to speed a deployment of the parachute by pulling theparachute from the protection element when the deployment projectile isdischarged.
 13. The unmanned aerial vehicle of claim 12, wherein thedeployment projectile is discharged from the unmanned aerial vehicle byat least one of igniting a propellant, releasing a propellant, releasinga compressed gas, releasing a compressed water, igniting a solid-fuelrocket, releasing a spring, or activating a solenoid.
 14. The unmannedaerial vehicle of claim 13, wherein the propellant is the deploymentprojectile.
 15. The unmanned aerial vehicle of claim 7, wherein: theprotection system: includes a plurality of parachutes coupled torespective different locations on the body of the unmanned aerialvehicle; and deploys a selected parachute of the plurality of parachutesthat is approximately on an opposite side of the body of the unmannedaerial vehicle with respect to the object.
 16. An aerial vehicle,comprising: a distance detector configured to measure a distance betweenthe aerial vehicle and an object; and a protection system configured todetermine an orientation of the aerial vehicle relative to the object,select a protection element, from a plurality of protection elements,for deployment based at least in part on the determined orientation, andactivate the protection element prior to an impact between the aerialvehicle and the object.
 17. The aerial vehicle of claim 16, wherein theplurality of protection elements include at least one of a parachute, anairbag, a propulsion element, or a spring.
 18. The aerial vehicle ofclaim 16, further comprising: a reorientation element configured toreorient the aerial vehicle to allow activation of the protectionelement in an intended direction with respect to the object.
 19. Theaerial vehicle of claim 16, wherein the protection element includes: aparachute; and a deployment projectile coupled to the parachute andconfigured to be discharged from the protection element to speed adeployment of the parachute by pulling the parachute from the protectionelement when the deployment projectile is discharged.
 20. The aerialvehicle of claim 16, further comprising: a safety monitoring systemconfigured to determine, based at least in part on the measureddistance, a risk of damage to the object resulting from an impactbetween the aerial vehicle and the object.